The Chiltern Hills are underlain by Chalk, predominantly what was traditionally called the Middle Chalk (now the lower part of the White Chalk Group) capped by the Top Rock - Chalk Rock complex. It is this series of chalk hardgrounds which effectively forms the spine of the Chiltern Escarpment. The Chalk dips gently into the London Basin, and the overlying basal Tertiary succession provides minor outliers around this northern rim of the basin. The other major geological event we have to recognise in this area is the re-routing of the Proto-Thames River during and following the Anglian glaciation, some 450,000 years ago. This created the landscape we currently see in much of the southern parts of the Chilterns. The route of the HS2 fast rail link passes straight across the Chilterns Area of Outstanding Natural Beauty (AONB) and the geology underlying this region is being impacted during tunnelling; some concerns will be raised regarding the tunnelling under the Chilterns, the geology it will encounter and its impact on Chalk aquifer and the surrounding AONB.

Dr. Haydon Bailey, Geological Adviser, The Chiltern Society

Minibiography

Haydon Bailey graduated in Geology a long time ago from the University of Sheffield; he has a PhD in Chalk micropalaeontology (from Plymouth), is a Chartered Geologist and has worked as a consultant stratigrapher in the oil and gas industry for over forty years. He still specialises in Upper Cretaceous Chalk stratigraphy, although his career has led to projects throughout much of the geological time scale around Europe, Africa and the Middle East. He recently retired for the position of co-Director of Network Stratigraphic Consulting Ltd., a company he co-founded some 25 years ago. He's a past Chairman and Industrial Liaison Officer of The Micropalaeontological Society and a past President of the Geologists' Association. He still serves on the GA Council as Chair of the Curry Fund and Chair of the Awards committee. Between 2012 and 2020 he was Honorary Lecturer on the M.Sc. in Applied & Petroleum Micropalaeontology at the University of Birmingham. He also holds the position of Geological & Environmental Adviser to the Chiltern Society (since 2008), where his initial brief was to prepare a report on the underlying geology of the Misbourne valley; subsequently this valley became the preferred route for HS2. This project still takes up too much of his time. More recently he has become increasingly involved in the preservation of Chalk Streams. He's married to a talented musician, has two children, one a Speech and Language therapist, the other flies people on stage and film sets and he has three brilliant grandchildren.

For those unable to attend the presentation in person we will also be broadcasting the talk on Zoom. Follow the link.

(Header image via HS2)